Automatic shut-off valve.



, bM-TENTBD DEC. s, 1903. N. G- LOQKB. v AUTOMATIC SHUT-OFF VALVE.

APPLICATION FILED D110. 22, 1908. v 2 SHEETS- SHEET 1.

R m m 0 M WI TN E55 E 5- N0 MODEL.

' v PAT-ENTED DEC. 8., 1903 N. C. LOCKB. AUTOMATIC SHUT-OFF VALVE.

APPLICATION FILED DEC. 22. 1902.

I 2 SHEETS-SHEET 2,

WITrJ 5555 Y "r mmms Pz'rzns co. PHoYuu'mu. WASHINGTON n c UNITED STATESPatented. December 8, 1903.

PATENT OFFICE.

REGULATOR COMPANY, OF SALEM, MASSACHUSETTS.

AUTOMATIC SH-UT-OFF VALVE.

SPECIFICATION forming part of Letters Patent No. 746,640, dated December8,. 1903. Application filed December 22, 1902. Serial No. 136,126. (Nomodel.)

To all whom it may concern:

Be it known that I, NATHANIEL O. LOCKE,

- of Salem, in the county of Essex and Stateof Massachusetts, haveinvented a new and useful Improvement in Automatic Shut- OE Valves, ofwhich the following is a specification.

My invention relates to automatic shut-oft valves especially adapted tobe located in the main supply-pipe of a steam-plant between the boilerand-the engine and intended tov steam-inlets, one above and one belowthe piston, one of these inlets being connected with the steam supply orboiler and the other with some portion of the main supply-pipe on theoutlet side of the valve. So long as these pressures are equal the valveremains in its normal position; but when the pressure on theoutlet sideis lowered materially, as

by a break in the pipe, the pressure on the inlet side or below thepiston being unbalanced by pressure above it becomes sufficient to liftthe piston and start. the valve toward its seat, bringing it into therushof steam, which closes it. Valves have also been made to close bythe rush of steam alone, the valve in this case standing normallysomewhat in the passage through whichthe steam passes and beingsufficiently heavy not to be closed by the steam in its ordinarymovement, but

only when pressure on the outlet side is so reduced that a rush iscaused. In either case there is a tendency on the part of the steam inits ordinary flow through the valve-opening to suck the valve onto itsseat. This is especially true in the first class of valves, abovereferred to, where the wire drawing of steam tends to reduce thepressure above thepiston. To operate successfully, therefore, themovable parts of these valves must be just heavy enough towithstand thissucking tendencyof the steam and not too heavy, or

the valve will notshut promptly when abreak occurs. Valves of the samesize are approximately of the same Weight; but variations in weightexist and steam-pressures vary, so that when the weight of a valve'isrelied upon to hold it open one cannot be positive that it will do so,especially in a case where the rush of steam alone is relied upon toclose it. My invention is intended to overcome these difficulties byapplying one or more weights, which may be adjusted in amount to assistin holding the valve off its seat, balancing it according to the normalflow of steam, so that it will not close under ordinary conditions, butwill close when required, and it will be seen that myinvention isequally applicable to the two types of valves to which I have referred,and I have shown it in the drawings applied to valves of both forms. Itis also evident that one or more weights may be applied by other meansand in other Ways than are shown in the drawings. In the drawings,however, I have shown preferred forms of construction.

Figure l is a vertical section of a shut-0E valve having means forpositively closing the valvenamely, a piston and cylinder. .Fig.

:2 shows a valve structure in which such positive means for operatingthe valve are omitted, the valve being adapted to be closed by anyincreased rush of steam abovea certain amount. The lower part of thestructure, being like that shown in Fig. 1, is omitted. Fig. 3 is across-section on line 3 3 of Fig. 2.

A is a casting provided with a steam-inlet A and a steam-outlet A thecasting being so shaped in itsinterior as to form achamber A divided bya diaphragm A having the passage B therethrough adapted to beclosed bythe valve B. This valve B has a chambered cylindrical bearingb screwedto its under surface at b. This chambered cylindrical bearing 19 isclosed at the bottom, with the exception of an opening through whichpasses the set-rod O. The bottom. of the chamber A is closed, by a diska, from which projects upwardly acyliudrical bearing a, in which slidesthe valve-bearing b. The setrod'O has an expanded end 0, adapted to bemoved vertically in the chamber in the bearing 1), so that there is acertain. amount of lost motion between the valve B and the setrod 0.

The disk a has an opening through its middle provided with astuffing-box a down through which the set-rod 0 passes, and it also hasspider-arms 0t extending downward and meeting in a hub a The lowerportion 0 of the set-rod O is threaded and passes through a threadedopening in the hub a its lower end being provided with a hand-wheel 0this whole structure being such that by means of the set-rod C the exactposition of the valve B with relation to the opening B in the diaphragmmay be adjusted to bring it sufficiently into the steam-current to beclosed if the force of the current increases materially and yet toremain open under ordinary conditions. If the valve sticks, it may bemoved away from its seat by withdrawing the set-rod C until itsenlargement o engages with the bottom of the chamber in the cylindricalbearing 1). By screwing the valve onto its seat this valve may be usedat any time as a throttle-valve, and yet because of the lost motionbetween the enlargement of the set-rod and the cylinder the valve willbe free to move Within certain limits when required to do so in cases ofemergency.

The valve B has a valve-rod B extending up through a bushing in the topof the casting A, and, as shown in Fig. 1, it has attached near itsupper end a piston B which slides in a cylinder D, forming part of acasing D. This cylinder has two small pipes leading into it. The pipe d,extending from the bottom of the cylinder, leads to a coupling, (notshown,) with the main steam-pipe on the inlet side of the shut-offvalve, while the pipe d extends from the upper part of the cylinder,connecting the chamber above the piston with the main steam-pipe on theoutlet side of the shut-off valve. Under ordinary circu mstanoes,thepressure on both sides of the sh ut-off valve being equal, the piston Band consequently the valve B, when once properly set will retain itsposition such that the passage B' will be open, whereas any weakening ofthe pressure above the piston, such as might be caused by a breakage inthe steampipe with which it connects, will allow the pressure on thesideof the shut-01f valve acting through the pipe dto lift the piston, andconsequently start the valve B toward its closing position, carrying itinto the body of steam which fills the chamber A in the casting A and isrushing toward the break. The valve will thus be closed and held closedby the pressure behind it, so that all further escape of steam will beprevented.

' The valve B tends to remain open owing to its own weight and thefriction between the piston and cylinder; but as it is desirable toadjust a valve according to the peculiar conditions under which it is tobe used I have provided means for the purpose, comprising a rocker-armE, which is connected by a link 6 with the top of the valve-rod 13*.This rocker-arm E is mounted on a rock-shaft F, one end of which lies ina bearingf, cast with the casing D, its other end passing throughastuffing-boxf and carrying a second rockerarm F outside the casing D. Aweight F of sufficient size may be hung on the arm F to cooperate withthe weight of the valve B and its parts and just counterbalance theclosing effect of the steam. This construction will be understood byreference to Fig. 3, which shows the means for mounting the rockshaftand the relation of the rocker-arms. By adjusting the location of thevalve B with relation to the opening B and'also by adjusting the weightF the valve may be rendered very delicate in its balance, so that itwill close with great promptness in case of accident. Moreover, if theweight be removed when the valve is in use, whether by hand orautomatically, the Valve will immediately close. It may thus be used asan emergency shut-off even when there is no break in the plpe.

I have shown in Fig. 2 my weight attachment applied to the other form ofvalve above referred to, that in which the cylinder and piston areomitted, and the valve depends for its closing upon the suction andimpetus caused by a sudden increase in the rush of steam through theopening B if at any time there is a breakage in the main pipe on theengine side of the valve. In this case the valve-stem B is extended up,as before, through a suitable opening in the top of the casing A and isthere pivotally connected directly with the, rocker-arm E, projectingfrom the rock-shaft F, carrying the second rocker-arm F, with a weight FIn this case it is evidentthat the position of the valve must be moredelicately adjusted, for the piston and cylinder being absent theelement of friction is lacking, as well as the means for positivelystarting the valve. The valve must therefore be located nearer its seat.In this case the stem of the valve serves somewhat asa guide; but itisnot necessary for that purpose, provided the portion b, extending belowthe valve B and forming part of it, is sufti ciently long and has asufiicient bearing in the part a to keep the valve in proper horizontalposition.

In the construction shown in Fig. 2 it is sometimes desirable to use aclosing-weight, so that when the weight F is removed the valve willstart to its seat immediately. For this purpose I have shown in dottedlines a rocker-arm G, mounted on the rock-shaft F and carrying at itsouter end a weight g, which will be sufficient when the weight F hasbeen removed to start the valve to its seat. This is shown in full linesin Fig. 3.

When suction is not depended upon to start the valve, I prefer to makeits upper surface conical, as shown in Fig. l, as the ordinary flow ofsteam will not tend to suck up a valve of this shape.

The value of this invention will be fully appreciated by all thoseskilled in the art when it is considered that it is necessary in anautomatic valve of this character that it shall close almost instantlywhen necessity requires and yet shall always remain openexceptinanemergency. By meansofweights applied to the valve its delicacymay be adjusted to suit any given case, and less care may be taken inthe weight of the metal of which the valve is made.

I have described my invention in connection with a steam system, as thatis the most frequent use to which it is likely to be put; but it isevident that valves of this construction may be used elsewhere for thepurpose of an automatic shut-off.

While I have described the valve B as moving vertically, it is evidentto one skilled in the art that by changing the arrangement ofweight-carrying levers they may be applied to a horizontally-movingvalve without departing from the spirit of my invention,which relatesnot to the exact means whereby the weighting is accomplished, but to theweighting of a valve of this character, however it may be accomplished.

What I claim as my invention is- 1. In an automatic shut-off valve, acasing having a steam-chain ber provided with an inlet and an outlet, aperforated diaphragm dividing said stearn-chamber horizontally, a valvelocated below the perforation in said diaphragm, and adapted to closesaid peforation, said valve having an upwardly-projecting stem, incombination with a rock-shaft carrying a rocker-arm connected with saidvalve'stem, and a second rocker-arm provided with weighting meansadapted to act with the weight of said valve to hold said valve normallyfrom closing said perforation, as described.

2. In an automatic shut-off valve, in combination a casing containing asteam-chamber having an inlet and an outlet, a perforated diaphragm, avalve adapted to close the perforation in said diaphragm and held offits seat by gravity, said valve being provided with anupwardly-projecting stem carrying a piston at its upperend, a cylindermounted above said casing, said piston being located within saidcylinder, two steam-inlets entering said cylinder, one above and theother below said piston, a rock-shaft carrying two rocker-arms, oneconnected with said valvestem and the other adapted to be adjustablyweighted, as and for the purposes set forth.

3. In an automatic shut-off valve, a casing containing a steam-chamberand having an inlet and outlet, a perforated diaphragm dividing saidchamber into two parts, a valve free to move toward and from saiddiaphragm and adapted when in its upward position to close theperforation in said diaphragm, means slidably connected with said valvesuch as a weight connected with said valve and adapted to move it towardits seat, and means such as a weight also connected with said let and anoutlet, a perforated diaphragm dividing said steam-chamber, a valvelocated below the perforation in said diaphragm and adapted to closesaid perforation, said valve having an upwardly-projecting stem and apiston mounted thereon, in combination with acylinder mounted above saidcasing, said piston being located in said cylinder, said cylinder alsobeing providedwith two steaminlets, one entering it above and the otherbelow said piston, said inlets being adapted to be connected with thesteam system, one on the inlet side of the diaphragm, the other on theoutlet side thereof, and a rock-shaft carrying a weighted rocker-armconnected with said valve-stem, as and for the purposes set forth.

5. In an automatic shut-off valve, acasing having a steam-chamberprovided with an inlet and an outlet, a perforated diaphragm dividingsaid steam-chamber, a valve located below the perforation in saiddiaphragm and adapted to close said perforation, said valve having anupwardly-projecting stem and a piston mounted thereon, in combinationwith a cylinder mounted above said casing, said piston being located insaid cylinder, said cylinder also being provided with two steaminlets,one entering it above and the other below said piston, said inlets beingadapted to be connected with the steam system, one on the inlet side ofthe diaphragm, the other on the outlet side thereof, and a rock-shaft.

viding said steam-chamber horizontally, a

valve located below the perforation in said diaphragm and adapted toclose said perforation, said valve having an upwardly-projecting stemand a downwardly-projecting hollow bearing, said casing also beingprovided with an upwardly-projecting hollow bearing adapted to receivethe bearing projecting from said valve, and to form a guide therefor,said valve also being provided with a set rod adapted to adjust thelower position of said valve, said valve-bearing being capable of asliding upward movement with relation to the end of said adjusting-rod,as and for the purposes described.

'7. In an automatic shut-off valve, a casing having a steam-chamberprovided with an inlet and an outlet, a perforated diaphragmdividingsaid steam-chamber horizontally, a valve located below theperforation in said & 746,640

diaphragm and adapted to close said perforathe'valve may be adjustedwith relation to its [0 tion, said valve having adownwardly-projectseat, as described.

ing bearing, said casing also being provided In testimony whereof Ihereunto set my with an upwardly-projecting hollow bearing name this11th day of December, 1902. adaptedtoreeeivethebearingprojeetingfromsaid valve and to form a guide therefor, in NATHANIEL LOOKE' combinationwith a rock-shaft suitably con- Witnesses:

nected to said valve and carrying a weighted GEORGE O. G. OOALE,

rocker-arm whereby-the normal position of I M. E. FLAHERTY.

